//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

// UNSUPPORTED: c++03, c++11, c++14, c++17

// <iterator>

// move_sentinel

// template <class Iter, class Sent>
//   constexpr bool operator==(const move_iterator<Iter>& x, const move_sentinel<Sent>& y);

#include <iterator>
#include <cassert>

#include "test_macros.h"
#include "test_iterators.h"

template<class T, class U> concept HasEquals = requires (T t, U u) { t == u; };
template<class T, class U> concept HasNotEquals = requires (T t, U u) { t != u; };
template<class T, class U> concept HasLess = requires (T t, U u) { t < u; };

static_assert(!HasEquals<std::move_iterator<int*>, std::move_sentinel<char*>>);
static_assert(!HasNotEquals<std::move_iterator<int*>, std::move_sentinel<char*>>);
static_assert(!HasLess<std::move_iterator<int*>, std::move_sentinel<char*>>);

static_assert( HasEquals<std::move_iterator<int*>, std::move_sentinel<const int*>>);
static_assert( HasNotEquals<std::move_iterator<int*>, std::move_sentinel<const int*>>);
static_assert(!HasLess<std::move_iterator<int*>, std::move_sentinel<const int*>>);

static_assert( HasEquals<std::move_iterator<const int*>, std::move_sentinel<int*>>);
static_assert( HasNotEquals<std::move_iterator<const int*>, std::move_sentinel<int*>>);
static_assert(!HasLess<std::move_iterator<const int*>, std::move_sentinel<int*>>);

template <class It>
constexpr void test_one() {
  char s[] = "abc";
  const auto it = std::move_iterator<It>(It(s));
  const auto sent1 = std::move_sentinel<sentinel_wrapper<It>>(sentinel_wrapper<It>(It(s)));
  const auto sent2 = std::move_sentinel<sentinel_wrapper<It>>(sentinel_wrapper<It>(It(s + 1)));
  ASSERT_SAME_TYPE(decltype(it == sent1), bool);
  assert( (it == sent1));
  assert(!(it != sent1));
  assert(!(it == sent2));
  assert( (it != sent2));
  assert( (sent1 == it));
  assert(!(sent1 != it));
  assert(!(sent2 == it));
  assert( (sent2 != it));
  static_assert(!HasEquals<decltype(sent1), decltype(sent1)>);
  static_assert(!HasLess<decltype(sent1), decltype(sent1)>);
}

constexpr bool test() {
  test_one<cpp17_input_iterator<char*>>();
  test_one<cpp20_input_iterator<char*>>();
  test_one<forward_iterator<char*>>();
  test_one<bidirectional_iterator<char*>>();
  test_one<random_access_iterator<char*>>();
  test_one<contiguous_iterator<char*>>();
  test_one<three_way_contiguous_iterator<char*>>();
  test_one<char*>();
  test_one<const char*>();

  return true;
}

int main(int, char**) {
  test();
  static_assert(test());

  return 0;
}
